1. Field of the Invention
The present invention relates to an automatic headlamp switching system, and more specifically to an automatic headlamp switching system for motor vehicles having attached accessory units.
2. Description of the Prior Art
When accessory units, such as snowplows, are attached to a motor vehicle, it is often necessary to provide a lighting source for the accessory unit because the vehicle lighting source or vehicle headlamps are often blocked or partially blocked by the snowplow itself. For example, on conventionally attached snowplows, headlamps are provided on the snowplow for illuminating the area in front of the vehicle and the snowplow. In order to illuminate the snowplow headlamps included on the conventional set-up, the required electrical connections from the vehicle to the snowplow had to be made and then a separate switch means for activating the snowplow headlamps had to be actuated. The vehicle headlamps are then turned off by a conventional switch in the interior of the vehicle. For example, see U.S. Pat. No. 4,280,062 issue to Miller et al on Jul. 21, 1981. In this conventional setup, more than one means for controlling the illumination of the vehicle headlamps and the snowplow headlamps was necessary.
The problem with the conventional headlamp set-up control system is the inconvenience of having the snowplow headlamp switch means on the snowplow itself or the difficulty and expense of installing the snowplow headlamp switch means on the instrument panel of the vehicle. Existing vehicle instrument dash boards contain so many tightly arranged components that it is difficult to find an open access for the installation of a snowplow headlamp switch. Vehicle dash boards are also normally styled to be aesthetically pleasing. The installation of an additional switch on the dash board frequently is time consuming and in an inconvenient location or is unsightly.